How do I convert AVI to MP4?

Upload your AVI file, ensure MP4 is selected as the output format, and click Process. The conversion happens locally in your browser using FFmpeg WebAssembly.

Will the file size decrease?

Usually yes, significantly. AVI files often use older, less efficient codecs. Converting to MP4 with H.264 typically reduces file size by 50-80% with similar visual quality.

Can I convert AVI files from old cameras?

Yes. This tool handles legacy AVI codecs like DivX, Xvid, and MJPEG, converting them to modern H.264 MP4 that plays on any device.

Why is AVI so much larger than MP4?

AVI often uses older codecs (DivX, Xvid) with less efficient compression. H.264 in MP4 achieves the same visual quality at a fraction of the file size thanks to modern compression techniques.

Is there a file size limit?

Files up to 2 GB are supported. Processing happens in your browser, so larger files just take more time.

Will quality be preserved?

Yes. Use the High quality preset for maximum fidelity. Since AVI typically uses older codecs, the modern H.264 encoding often looks just as good or better at a fraction of the size.

AVI to MP4 Converter

Convert AVI video files to modern MP4 format. Dramatically reduce file size while maintaining quality — free and private, runs in your browser.

Video File

Drop files here or click to browse

Max 10240.0 MB per file · drop multiple for batch

100% private — files never leave your device

Free — no sign up, no watermark

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How to Use AVI to MP4 Converter

Upload your AVI file by dragging it in or clicking Browse
MP4 is pre-selected as the output format
Click Process to convert using H.264 encoding
Download the smaller, modern MP4 file

Features

Convert AVI to MP4 with modern H.264 encoding
Dramatically reduce file size — MP4 is typically 2-5x smaller than AVI
Handles legacy codecs like DivX, Xvid, and MJPEG
Adjustable quality and resolution settings
Process files of any size directly in your browser
No sign-up, no watermark, no installation required

Frequently Asked Questions

How do I convert AVI to MP4?: Upload your AVI file, ensure MP4 is selected as the output format, and click Process. The conversion happens locally in your browser using FFmpeg WebAssembly.
Will the file size decrease?: Usually yes, significantly. AVI files often use older, less efficient codecs. Converting to MP4 with H.264 typically reduces file size by 50-80% with similar visual quality.
Can I convert AVI files from old cameras?: Yes. This tool handles legacy AVI codecs like DivX, Xvid, and MJPEG, converting them to modern H.264 MP4 that plays on any device.
Why is AVI so much larger than MP4?: AVI often uses older codecs (DivX, Xvid) with less efficient compression. H.264 in MP4 achieves the same visual quality at a fraction of the file size thanks to modern compression techniques.
Is there a file size limit?: Files up to 2 GB are supported. Processing happens in your browser, so larger files just take more time.
Will quality be preserved?: Yes. Use the High quality preset for maximum fidelity. Since AVI typically uses older codecs, the modern H.264 encoding often looks just as good or better at a fraction of the size.

AVI to MP4 Converter

How to Use AVI to MP4 Converter

Features

Frequently Asked Questions

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